Jensen started his stunt career in the late '70s with the television pilot BJ and the Bear (1978). Among the actors he has doubled for are Ben Affleck (1999 in Dogma), Jason Mewes (2001 in Jay and Silent Bob Strike Back), and Rick Schroeder (2002 in Poolhall Junkies). Jensen served as stunt coordinator for films such as the drama The Tempest (1998, with John Glover and John Pyper-Ferguson), the comedy Deal of a Lifetime (1999), the action film One Man's Hero (1999), the thriller The Deep End (2001), and the comedy Stark Raving Mad (2002, along Gregory J. Barnett).

Further stunt credits in the '90s include the horror film Tremors (1990, with George Colucci and Jeff Imada), the television horror film Child of Darkness, Child of Light (1991, with Claudette Nevins and Alan Oppenheimer), the drama Barton Fink (1991), the television series Crossroads (1991), the fantasy film Super Mario Bros. (1993), the adventure film The River Wild (1994), the television series Deadly Games (1995, starring Christopher Lloyd), the thriller Hard Time (1996), the crime drama Last Man Standing (1996), the science fiction film Aasteroid (1997), the television drama Bella Mafia (1997, with Gina Philips and stunts by Leslie Hoffman), Roland Emmerich's science fiction thriller Godzilla (1998), and Bryan Singer's thriller Apt Pupil (1998, with Mickey Cottrell, Bruce Davison, and stunts by Dustin Courtney, Lane Leavitt, and Ken Bates).